This invention concerns a device for laying and stretching sheets of covering, for example, waterproof sheets made of synthetic material, suitable for protecting the surfaces of hydraulic structures, and roofs of civil, industrial and similar buildings. As is known, in order to lay waterproof coverings on flat and similar surfaces, the covering sheet or sheets are normally secured, along one edge of the surface to be covered, for example, by means of gun-riveting; after which the sheets are stretched out by hand and then secured by means of traditional fasteners, such as screws, nails and the like. With anchoring and stretching systems of the mentioned type, the laying and stretching operation proves to be rather difficult, especially when the surfaces to be covered are extensive; furthermore, stretching the sheets by hand proves to be an operation which is both laborious and difficult to carry out within a comparatively short period of time.
The scope of this invention is to provide a device for laying and stretching covering sheets for protecting surfaces in general, which enables the operations of securing and stretching of the sheets themselves to be carried out automatically and with the greatest of ease. A further scope of this invention is to provide a device suitable for laying waterproof sheets on flat, sloping and/or slightly curved surfaces of any shape and size.